/*
 *  Copyright (C) 2005 Francesco Romani <fromani@gmail.com>
 * 
 *  This Software is heavily based on tcvp's (http://tcvp.sf.net) 
 *  mpeg muxer/demuxer, which is
 *
 *  Copyright (C) 2001-2002 Michael Ahlberg, Mans Rullgard
 *  Copyright (C) 2003-2004 Michael Ahlberg, Mans Rullgard
 *  Copyright (C) 2005 Michael Ahlberg, Mans Rullgard
 *
 *  Permission is hereby granted, free of charge, to any person
 *  obtaining a copy of this software and associated documentation
 *  files (the "Software"), to deal in the Software without
 *  restriction, including without limitation the rights to use, copy,
 *  modify, merge, publish, distribute, sublicense, and/or sell copies
 *  of the Software, and to permit persons to whom the Software is
 *  furnished to do so, subject to the following conditions:
 *
 *  The above copyright notice and this permission notice shall be
 *  included in all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 *  HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 *  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 *  DEALINGS IN THE SOFTWARE.
 */

#include <string.h>
#include <stdarg.h>
#include <assert.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdint.h>


#include "mpeglib.h"
#include "mpeglib_private.h"

/** mempry handling hooks */
static mpeg_macquire_fn_t mem_acquire = malloc;
static mpeg_mrelease_fn_t mem_release = free;


void mpeg_set_mem_handling(mpeg_macquire_fn_t acquire,
                      mpeg_mrelease_fn_t release)
{
    assert(acquire != NULL);
    assert(release != NULL);

    mem_acquire = acquire;
    mem_release = release;
}
        

/** logging hooks */
static void *logdest = NULL;
static mpeg_log_fn_t logger = mpeg_log_file;

void mpeg_set_logging(mpeg_log_fn_t nlogger, void *nlogdest)
{
    assert(nlogger != NULL);
    assert(nlogdest != NULL);

    logger = nlogger;
    logdest = nlogdest;
}

mpeg_res_t mpeg_log(int level, const char *fmt, ...)
{
    int ret = MPEG_OK;
    va_list ap;

    assert(logger != NULL);
    if(logdest == NULL) {
        logdest = stderr;
    }

    va_start(ap, fmt);
    ret = logger(logdest, level, fmt, ap);
    va_end(ap);
    return ret;
}


static size_t mpeg_file_read(mpeg_file_t *MFILE, void *ptr, 
                             size_t size, size_t num)
{
    assert(NULL != MFILE);
    assert(NULL != ptr);
    return fread(ptr, size, num, MFILE->priv);
}

static size_t mpeg_file_write(mpeg_file_t *MFILE, const void *ptr, 
                              size_t size, size_t num)
{
    assert(NULL != MFILE);
    assert(NULL != ptr);
    return fwrite(ptr, size, num, MFILE->priv);
}

static int mpeg_file_seek(mpeg_file_t *MFILE, uint64_t offset, int whence)
{
    assert(NULL != MFILE);
    return fseek(MFILE->priv, offset, whence);
}

static int64_t mpeg_file_tell(mpeg_file_t *MFILE)
{
    assert(NULL != MFILE);
    return ftell(MFILE->priv);
}

static int64_t mpeg_file_get_size(mpeg_file_t *MFILE)
{
    struct stat buf;
    int res;
    
    assert(NULL != MFILE);

    res = fstat(fileno(MFILE->priv), &buf);
    if(res != 0) {
        return -1;
    }
    return (int64_t)buf.st_size;
}

static int mpeg_file_eof_reached(mpeg_file_t *MFILE)
{
    assert(NULL != MFILE);

    return (feof(MFILE->priv)) ?TRUE :FALSE;
}

mpeg_file_t* mpeg_file_open(const char *filename, const char *mode)
{
    mpeg_file_t *MFILE = mpeg_mallocz(sizeof(mpeg_file_t));
    FILE *f = NULL;
    if(NULL != MFILE) {
        f = fopen(filename, mode);
        if(NULL != f) {
            MFILE->streamed = FALSE;
            MFILE->priv = f;
            
            MFILE->read = mpeg_file_read;
            MFILE->write = mpeg_file_write;
            MFILE->seek = mpeg_file_seek;
            MFILE->tell = mpeg_file_tell;

            MFILE->get_size = mpeg_file_get_size;
            MFILE->eof_reached = mpeg_file_eof_reached;
        }
    }
    return MFILE;
}

mpeg_file_t* mpeg_file_open_link(FILE *f)
{
    mpeg_file_t *MFILE = mpeg_mallocz(sizeof(mpeg_file_t));
    MFILE->streamed = TRUE;
    MFILE->priv = f;
        
    MFILE->read = mpeg_file_read;
    MFILE->write = mpeg_file_write;
    MFILE->seek = mpeg_file_seek;
    MFILE->tell = mpeg_file_tell;
            
    MFILE->get_size = mpeg_file_get_size;
    return MFILE;
}

int mpeg_file_close(mpeg_file_t *MFILE)
{
    int err = 0;
    
    assert(NULL != MFILE);
    assert(NULL != MFILE->priv);
    
    if(!MFILE->streamed) {
        err = fclose(MFILE->priv);
    }
    if(!err) {
        mpeg_free(MFILE);
    }
    return err;
}
    
static const char* mpeg_log_level_string(int level)
{
    const char *str = NULL;
    switch(level) {
    case MPEG_LOG_ERR:
        str = "[ERR] ";
        break;
    case MPEG_LOG_WARN:
        str = "[WRN] ";
        break;
    case MPEG_LOG_INFO:
        str = "[INF] ";
        break;
    default:
        str = "[???] ";
        break;
    }
    return str;
}

mpeg_res_t mpeg_log_file(void *dest, int level, const char *fmt, va_list ap)
{
    fputs(mpeg_log_level_string(level), dest);
    vfprintf(dest, fmt, ap);
    return MPEG_OK;
}


mpeg_res_t mpeg_log_null(void *dest, int level, const char *fmt, va_list ap)
{
    return MPEG_OK;
}

void* _mpeg_real_malloc(const char *where, int at, size_t size)
{
    void *ptr = NULL;
    if(size > 0) {
        ptr = mem_acquire(size);
    }
    if(NULL == ptr) {
        mpeg_log(MPEG_LOG_ERR, "(%s) at line %i: "
                "unable to alloc %lu bytes\n",
                where, at, (unsigned long)size);
    }
    return ptr;
}
    
void* _mpeg_real_mallocv(const char *where, int at, size_t size, uint8_t val)
{
    void *ptr = _mpeg_real_malloc(where, at, size);
    if(NULL != ptr) {
        memset(ptr, val, size);
    }
    return ptr;
}

void mpeg_free(void *ptr)
{
    mem_release(ptr);   
}

void mpeg_fraction_reduce(mpeg_fraction_t *f)
{
    int n = f->num;
    int d = f->den;

    while(n > 0) {
        int t = n;
        n = d % n;
        d = t;
    }

    f->num /= d;
    f->den /= d;
}

static const uint32_t crc_table[256] = {
    0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
    0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
    0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7,
    0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
    0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3,
    0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
    0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef,
    0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
    0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb,
    0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
    0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
    0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
    0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4,
    0x0808d07d, 0x0cc9cdca, 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
    0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08,
    0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
    0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc,
    0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
    0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050,
    0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
    0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
    0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
    0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1,
    0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
    0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5,
    0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
    0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9,
    0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
    0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd,
    0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
    0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
    0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
    0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2,
    0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
    0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e,
    0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
    0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a,
    0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
    0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676,
    0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
    0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
    0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
    0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
};

uint32_t mpeg_crc32(const uint8_t *data, int len)
{
    uint32_t crc = 0xffffffff;
    int i;
    
    for (i = 0; i < len; i++) {
        crc = (crc << 8) ^ crc_table[((crc >> 24) ^ *data++) & 0xff];
    }
    return crc;
}


